... because box office analysts say Twi-hards have not abandoned their breathless obsession with undead stalker Edward Cullen and his doormat love interest, nor will they suddenly find something else to like in 2012.

"We may be looking at the highest-grossing opening weekend of all-time," warns Exhibitor Relations box office analyst Jeff Bock. "Twi-hards have become even more fanatical than Potterheads...and now they're the only game in town."

So exactly how much of filthy vampire lucre will be spent on this two-part mess? Well, the first part, due out Nov. 18, will be a juggernaut all by itself. And the second half, in which half-vampire Renesmee (yep, really) presumably toddles for her young un-life, will garner even more.

"Expect Breaking Dawn: Part I to debut with upwards of $150 million," Bock tells me, "and Part II to soar even higher!"

Let's compare that to other recent film franchises. The first installment of The Lord of the Rings earned about $66 million on its opening weekend. The Two Towers? About $62 mil, while the trilogy finale brought in $72 million during its debut days. (Worldwide overall earnings, natch, have been much higher, with King alone grossing more than a billion bucks across the planet.)

As for the Harry Potter series, the first installment brought in more than $90 million in its opening weekend. By the time the last film came around, the franchise had garnered so many fans that Harry Potter and the Deathly Hallows Part 2 raked in $169 million in its first few days alone.

Why control-freak vampires earn more money than hobbits and dragons these days is anyone's guess. Why they'll still earn more money in 2012 is an even sadder mystery. Perhaps a box office vampire with the ability to read the minds of America's hausfraus will be able to tell us.

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